Learn Farsi: نود معلم و صد دانش‌آموز در مدرسه هستند. - Ninety teachers and one hundred students are in the school.

In Farsi, nouns that come directly after a number always stay in the singular form. So instead of saying 'ninety teachers', Farsi literally says 'ninety teacher' (نود معلم) and 'one hundred student' (صد دانش‌آموز).

The translation says 'one hundred', but the sentence only uses the word صد. Where is the word for 'one'?

The word صد on its own means 'one hundred'. You do not need to add the number one (یک) in front of it.

If the nouns are singular, why is the verb at the end (هستند) in the plural form?

Even though the nouns stay grammatically singular after a number, their meaning is plural. Because teachers and students are people, Farsi grammar requires the verb to match the plural meaning, so we use the plural form for 'are' (هستند).

What are the two parts of the compound word for student (دانش‌آموز)?

دانش means 'knowledge' and آموز relates to learning or teaching. Together, a دانش‌آموز is a 'knowledge-learner', which is the standard word for a school student.